Confocal Endomicroscopy Shows Food-Associated Changes in the Intestinal Mucosa of Patients With Irritable Bowel Syndrome

      Background & Aims

      We investigated suspected food intolerances in patients with irritable bowel syndrome (IBS) using confocal laser endomicroscopy (CLE) for real-time visualization of structural/functional changes in the intestinal mucosa after food challenge. Patients with functional changes after food challenge (CLE+) were placed on personalized exclusion diets and followed up for long-term symptom relief.


      Thirty-six IBS patients with suspected food intolerance and 10 patients with Barrett’s esophagus (controls) without IBS symptoms were examined by CLE at University Hospital Schleswig-Holstein (Kiel, Germany). Diluted food antigens were administered directly to the duodenal mucosa through the working channel of the endoscope. Epithelial breaks, intervillous spaces, and the number of intraepithelial lymphocytes (IEL) were measured before and after the food challenge. CLE+ patients were placed on exclusion diets, given symptom score questionnaires, and followed up for 1 year; controls resumed their previous diet.


      CLE showed a real-time response to food antigens in 22 of 36 patients; no responses were observed in 14 of 36 patients (CLE-) or any of the controls. Baseline IELs were significantly higher in CLE+ than CLE- subjects (P = .004); numbers increased significantly after food challenge (P = .0008). Within 5 minutes of exposure of CLE+ patients to food antigens, IELs increased, epithelial leaks/gaps formed, and intervillous spaces widened. Epithelial leaks and intervillous spaces also increased significantly in CLE+ vs baseline (both P < .001). The concordance of IELs measured by CLE and conventional histology was 70.6%; they did not correlate (P = .89; r2 = 0.027). Symptom scores improved more than 50% in CLE+ patients after a 4-week exclusion diet and increased to 74% at 12 months; symptoms continued in CLE- patients.


      Based on CLE analysis of IBS patients with a suspected food intolerance, exposure to candidate food antigens caused immediate breaks, increased intervillous spaces, and increased IELs in the intestinal mucosa. These changes are associated with patient responses to exclusion diets. Registered at (registration number: NCT01692613).


      Abbreviations used in this paper:

      CI (confidence interval), CLE (confocal laser endomicroscopy), FODMAP (fermentable oligo-, di- and monosaccharides and polyols), GI (gastrointestinal), IBS (irritable bowel syndrome), IEL (intraepithelial lymphocyte), IVS (intervillous space), SEM (scanning electron microscopy)
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      Linked Article

      • Nonceliac Wheat Sensitivity in the Context of Multiple Food Hypersensitivity: New Data From Confocal Endomicroscopy
        GastroenterologyVol. 148Issue 3
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          We enjoyed reading the article by Fritscher-Ravens et al who showed, by confocal endomicroscopy, that candidate food antigens caused immediate duodenal mucosa damage in irritable bowel syndrome (IBS) patients with a prolonged clinical history of symptoms after meals.1 Their in vivo data add evidence to the relationship between IBS and food allergy and seem to reinforce our hypothesis that a percentage of “nonceliac wheat sensitive” (NCWS)–patients with an IBS-like clinical presentation could suffer from non–immunoglobulin E-mediated wheat allergy.
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